Refrigerating apparatus



June 4, 1946. T. c. KlLLoRAN REFRIGERATING APPARATUS `Filed Aug. 20,1942 Patented June 4, 1946,

r i v2,401,426

' UNITED. STATES PATENT oFFicr.

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Appllcalizrisi:istxglllilgetlhgl 14. Claims. l

This invention relates to refrigerating apparatus and is a continuationof all parts common to applicant's abandoned application Serial No.292,487 filed August 29, 1939 which was copending herewith. Moreparticularly this invention relates to a refrigerating apparatus for useon trucks and semi-trailers.

The rst object of this invention is to provide 'an automaticallycontrolled refrigerating apparatus powered by a one-cylinder internalcombustion engine. So much difficulty has been encountered heretofore infunctioning automatic refrigerating mechanism controls from pressurechanges in the manifold of a four-cycle, single cylinder internalcombustion engine, that it is common practice to employ continuouslyoperating gas engine refrigerating systems with all the drawbacks thatsuch continuously operating systems entail. The difilculty arises fromthe fact that a single cylinder, vfour-cycle internal combustion engine,having only one intake stroke for each four cycles, is unable tomaintain in the manifold a reduced pressure which is suiciently constantto indicate continuous functioning of the engine. One of the features ofapplicant's invention is the provision of a, vacuum control which willestablish in a vacuum chamber a fairly constant reduced pressure orvacuum while the engine is running. This vacuum control is capable ofisolating the vacuum chamber from the pressure increases in the manifoldoccurring during the three non-intake cycles of the engine.

A second object of this invention closely associated with the firstobject is to employ the substantially constant vacuum as a means ofdisabling a starter circuit which initially connected an engine starterto an electrical source of power so as to turn over the ilywheel of theinternal combustion engine and start the system.

Another object of this invention is to provide I a new and imprved meansfor stopping the refrigerating apparatus when a predetermined lowtemperature of the systems evaporator or cooling coils has been reached.In this connection, applicant employs a, superheat control bulb mountedon the suction side of the evaporator coils, together with a small boretube which transmits pressure changes from said bulb to a thermostaticexpansion valve for controlling the opening and closing of said valvewhich operates, when open, for admitting refrigerant to the evaporatorcoils at the inlet. Connected to the low side of the refrigeratingsystem, that is, to the suction side of the evaporator, is a bellowscon- 5 ceptionallylow pressure that will then be developed in thesuction line of the evaporator orv the low side of kthe compressor willcause this switch to close and thereby ground the magneto of theinternal c'ombustion engine which is supplying the necessary spark tokeep the engine operating.

A further object of this invention is to provide a choke controlresponsive to the substantially constant reduced pressure provided byapplicants vacuum control so as to facilitate the starting of the engine'by increasing the percentage of gasoline in the mixture delivered tothe internal combustion engine.

These and such other objects as may hereinafter appear are obtained inone embodiment of the invention shown in the drawing wherein arefrigerating apparatus powered by an internal combustion engine isshown in dotted lines with applicants vacuum control system shown insolid lines and the electrical circuits shown in either solid lines ordistinctive broken lines.

Continuing to refer to the drawing, the nui meral I0 identies asupporting base having a plurality of legs such as l2 and I4. Mounted onthe base l0 toward the back thereof is a condenser coil l5 extendingsubstantially the full width of the base I8. Adjacent to the condensercoil |6 is a refrigerating compressor AI8 and a four-cycle, singlecylinder internal combustion engine 20, both of which are mounted on thebase lll and which are maintained in operable relationship to each otherby a drive belt 22 which operates over pulleys in the conventionalmanner.

Conventional means for supplying the internal combustion engine withfuel and the necessary spark comprise a gas tank 24 supplying gasolineby conduit 26 to a carburetor 28 having a choke valve 38. The carburetor28 communicates with a manifold 32, which in turn communicates with thecylinder head. 34 indicates a magneto from which a conductor 36 isadapted to impress electrical potential onto the primary winding P of anignition transformer or coil 38. A circuit interrupter 40, connected inseries with the conductor 36 and said ignition coil primary, is operatedcoordinately with the engine to open the potential supply circuit forthe ignition coil primary and thus induce a high potential in the coilsecondary S and hence upon the engine spark plug 42 each ,time fuel iscompressed in the engine cylinder. The conductor forms part of adisabling circuit, herinafter described, which is shown by long dashes.Y Y

An electric powered starter 44 constitutes the means for cranking theinternal combustion enine 20. g 'I'he refrigerant circulatory systemincludes the compressor I0, the compressed gas leaving the head 40 ofthe compressor by the pipe s0 by which it isled tothe condenser andthence through a pipe 40 toa reservoir 00. Refrigerant may leave thereservoir 00 by the conduit 02 by which it reaches a valve 54, whichhereinafter will be referred to as the refrigerant supplyfvalve.v Whenthe refrigerant supply valve 04 is open, the refrigerant may continuethrough the conduit 00 to a thermostatic expansion valve 00 which ishereinafter referred to as the capillary control valve since it isoperably connected with the temperature responsive bulb 12 by the tube10 having a small bore. Whenthe capillary control valve 50 is open therefrigerant may flow therethrough and thev conduit 00 to the evaporator02.

Upon a predetermined rise in temperature of the wall portion of theevaporator 02 upon which the bulb 12 is mounted, increased pressure thusgenerated in said bulb will be communicated through the tube for openingthe capillary control valve 50 and thus permitting refrigerant to flowfrom the conduit 55 into the evaporator 62. The outlet or suction end ofthe evaporator 02, which is des ignated by the numeral 04, is connectedby a conduit 56 to the suction or low side 58-of the compressor I0. Itwill be appreciated that the evaporator 02 will be located in the spaceto be cooled and will be of whatever configuration is best adapted toperform thercooling function in that space.

Mounted on the base I0 in front of the compressor i0 is a switch panel14. On this panel 1.4 three switches are disposed, namely, a masterswitch 10, a starterbreak switch 18 and a disabling switch 80 fordsablingthe internal combustion engine and causing the refrigeratingapparatus to stop.

It will he understood that in rendering a refrigerating apparatusautomatic, oi' the type thus far described, it is necessary to start theapparatus when the temperature of the evaporator 02 has risen to apredetermined point. This necessitates energizing the electric starter44. After the internal combustion engine has commenced to function, itis necessary to open the electric circuit to the starter 44automatically. After the apparatus has functioned sufliciently long tolower the temperature of the evaporator 02 to a predetermined point, itis necessary to stop the internal combustion engine, and at this time tocondition the starter circuit so that it will function the starter whenthe evaporator rises to a selected temperature. Additionally applicanthas found it desirable vto positively and automatically control the owof refrigerant to the evaporator by means of the valve 54, therebyprecluding leak age of refrigerant through the expansion valve into theexpansion coils during shut-down periods without the necessity for afloat valve commonly used in other systems for this purpose. Applicantutilizes, therefore, three circuits which he identiiles as the startercircuit, the refrigerant control circuit, andthe disabling circuit.These will be described in order.

The starter circuit The starter circuit including the source of power 4conductor is shown in a solid line. 02 identifies the lmgrounded or"hot" line of an electrical source of power. This line is connectablethrough a solenoid switch-00, schematically shown, and a conductor 00-with the starter 44 which is grounded at 00. 'I'he solenoid switch 00isspringbiasedsoastobeopen whenits coil 02 is unenergixed. Theungrounded line 02 is tapped by a conductor 00 which leads through thecoil 02 of the solenoid switch 04 and thence to a post 04 of the masterswitch 10. As illustrated, the master switch 10 is a double-polesingle-throw knife switch. When the master switch 10 is in closedposition. current will ilow to a post 00 and thence by a conductor 00into the starter break switch 10. The starter break switch 10 is shownfor convenience as a multiple leaf switch wherein the leaves |00, |02,|04 and |00 are held at one end by insulators |00 and may be connectedto each other through contacts ||0 and I|2 and ||0 and ||0 dependingupon the position of an arm ||0 pivoted at |20 and biased toward itsfull line position by a spring |22. The position of the arm ||0 iscontrolled by a reciprocable link |24 responsive to a bellows |20. Theposition of the arm H0 shown in the drawing in solid lines is theposition occupied thereby when the bellows |20 is expanded, that is,when the bellows is not drawing against the spring |22.

Resuming the tracing of the starter circuit, the current is conductedthrough leaf |02, the contacts H2 and ||0 to the leaf |00 and thence outof the starter break switch 10 by the conductor |20 to the disablingswitch 00. The disabling switch is schematically shown and is similar tothe starter break switch 10. It has four leaves |30, |02, |04 and |00and four contact points |30, |40, |42 and |44. Its control arm bears thenumeral |40 and this control arm is pivoted at |40 and biased toward itsfull-line position by a spring |50. It moves in response to thereciprocable link |52 which in turn is controlled by a bellows |54.Resuming the tracing of the starter circuit, the conductor |20 isconnected to the leaf |02, which when the disabling switch 00 is in thecondition shown is conductively related to the leaf |00 by the contacts|30 and |40. The leaf |40 is grounded at |50.

The (refrigerant control circuit The refrigerant control circuit isshown in the drawing by a dot-dash line and comprises a conductor |50tapped to the ungrounded line 02 and leading to a post |00 of the masterswitch 10. When the master switch 10 is in the closed position, currentfrom the conductor |50 will reach the post |02 and thence by conductor|04 will reach the starter break Iswitch 10 where the conductor |04 isconnected to the leaf |04. When the contacts ||4 and ||0 of the starterbreak switch are in contact, the current will flow from the leaf |04 tothe leaf |00. Thence by a conductor |00, the current will becommunicated to a solenoid |00 of the refrigerant control valve 54. Thesolenoid |00 is grounded at |10.

,The disabling circuit for the internal combustion The numeral I `Themeans for controlling the disabling switch 80 The bellows |54 of thedisabling switch 80 is connected by a conduit |18 to the suction conduitI8 from the evaporator 82. The bellows works against the spring |80, thetension of which is so adjusted that the bellows |84 will not be able tomove the arm |48 to the open position of the disabling circuit switch 80until the pressure in the suction conduit 88 has dropped followingclosing of the valve 88 under controlof the bulb 12.

The means for controlling the starter break switch 78 'Ihe bellows |28of the starter break switch 18 is connected by a conduit |18 to a vacuumchamber |88. The vacuum chamber |80 is connected by a conduit |82 to avacuum control unit |84. 'I'he vacuum control unit |84 consistsessentially of a. double valve consisting of the valve unit |88 and the.valve unit |88. Valve unit |88 includes a wafer |88 normally held invalve-closing relation upon an annular seat |81 by the force of an ex`-pension spring |88 which bears upwardly against a reaction member |9|.Valve unit |88 includes a wafer |83 normally pressed in valve-closingrelation upon an inverted annular seat |95 about the walls of an inletchamber |92 of the casing |99 by the force of a spring 20| which reactsupon a plate 208 in said casing. A chamber |90 of the vacuum controlunit |84 communicates with the manifold 82 through a conduit |94,lwherefore upon the `starting of the engine and the consequent loweringof the pressure in the manifold, will cause air within the partsconnnected with the inlet side of the unit |84 to be withdrawntherethrough, such air passing into the chamber |92 from the conduit|82, thence through the valve |88 (of which the wafer |98 is thenunseated by the relatively higher pressure in the chamber |92) thencethrough holes 205 and 201 in the plate 203, valve |88 (of which thewafer |85 is then unseated by the relatively greater pressuretherebeneath) and thence through the chamber |90 and.the conduit' |94 tothe manifold 82. Substantial equalization of pressure on opposite sidesof the urr'it |84 will permit the wafers |85'and |93 to seat, closingtheir respective valves |88 and |88, and since these valves are inseries no substantial flow rate of air reversely through the unit, thatis, from the conduit |94 to the conduit |82, can occur.

By the arrangement described, therefore, the pressure in the vacuumchamber |80 will not follow the changes in pressure in the manifold 92but rather, during engin'e operation, will remain near the lowestpressure attained in the manifold 32 on each intake stroke of the fourcycle, single cylinder engine. As mentioned heretofore the pressure inthe manifold 80 of a single cylinder fourcycle engine does not remainvery constant because no suction is applied to the manifold on three ofthe four cycles of the engine, wherefore suction strokes occur at thelow frequency of one for each two engine revolutions. By applicantsarrangement, on the suction cycle of the engine 20, the comparativelylow pressure in the mani-- fold 80 will be communicated through thewafer valves |88 and |88 to the vacuum chamber |80 to establish arelatively low pressure therein. On the next three cycles of theinternal combustion engine 20 the pressure in the manifold 80 will risesubstantially, but this rise in pressure willA not be communicated tothe vacuum tank |80 because of the closing of the two wafer valves |88and |88. As will be understood from a description of the operation oi'this refrigerating apparatus,

6 this is exceedingly important because the maintenance of asubstantially constant low pressure in the vacuum chamber |88 maintainsthe bellows |28 of the starterv break switch 18 in contracted positionwithout permitting intermittent changes ot position which would causeintermittent opening and closing of the refrigerant'supply valve 84 andenergization of the engine starter circuit.

The choke control Referring now to the carburetor 28, the choke 30 iscontrolled by a linkage |94a which in turn |98 contracts and opens thechoke 30, therebyadmltting more air to the gas mixtureintroduced to themanifold 30. This occurs when the engine is running normally.

Operation In order that the full automatic functioning of applicantsdevice may be appreciated its operation will now be described. When themachine is not in functioning condition, the master switch 18 will beopen. At such a time the pressurein` the vsuction conduit 88 from theevaporator 82 will be high because the evaporator will approximate thetemperature of the space in which it is positioned. The bellows |54consequently will be expanded so that the arm |48 is in the solid lineposition shown in the drawing. Under such circumstances the contacts |38and |40 of the disabling switch will be closed while the contacts |42and |44 thereof will be open. In the case of the starter break switch18, the bellows 28 will be expanded so that the contacts |0 and ||2 willbe closed while the contacts ||4 and ||8 are open because the pressurein the conduit |18 and the vacuum chamber |80 will approximateatmospheric pressure. Also at this time, the bellows |98 will beexpanded because the pressure in the conduit |98 will be approximatelyat atmospheric pressure so that the choke 30 will close the air intake200 in which it is mounted. The refrigerant supply valve 54 will beclosed because its solenoid |88I is unenergized. The capillary controlor expansion valve 58 will be open lbecause the temperature in the end84 of the evaporator coil 82 will be suillciently great'for causing thebulb 12 to act through the tube 10 for holding'said valve 58 open.

It then beingdesired to bring down the temperature of the space in whichthe evaporator 82 is positioned, which means bringing down the`temperature oi' the evaporator, the master switch 18 is closed. Fromlthis time on the apparatus will function automatically and importantly,without excessive cycling. Upon the closing of the master switch 18 thestarter circuit, indicated by the solid transformer 38 and circuitinterrupter A40, to impress the required ignition potential upon theplug 42 at the proper times. Until the engine 20 actually commences tofunction. the various other circuits and the valves remain substantiallyin the condition in which they were prior to the closingof the switch16. The reason for this is that so long as the internal combustionengine 20 is being turned over solely by the starter 44 a sufiicientvacuum is not developed in the vacuum chamber |80 to aifect the bellows|26 of the starter break switch 18 or the bellows |96 controlling thechoke 30.

When the internal combustion engine 20 commences to function itimmediately develops a vacuum in the vacuum chamber |80 which issuiiicient to collapse the bellows |96 and open the choke so as to admitmore air through the air intake 200 to thegas mixture leading to themanifold. The vacuum in the chamber |80 is also sufficiently great tocollapse the bellows |26 and overcome the pull of the spring |22 wherebythe contacts U'and |2 are opened, which breaks the starter circuit. Whenthe starter circuit is broken, the coil 92 is deenergized which opensthe line to the starter 44, which ceases to function.

It will be noted that upon the movement of the arm ||8 of the starterbreak switch 18 into the dotted line position 202, the contacts ||4 andI6 close so that the refrigerant supply circuit is completed from thehot" line 82 through the solenoid |68 of the refrigerant supply valve 54to the ground |10. The solenoid |68 opens the valve 54 permittingrefrigerant to flow to and through `mally while the temperature of theevaporator 62 is lowered at a rate of speed depending upon the amount ofrefrigerating work to be done thereby. It will be appreciated that therewill not be any cycling of the internal combustion engine 20 because theinternal combustion engine 20 cannot be stopped excepting by the closingof the two contacts |42 and |44 of the disabling switch 80 which havethe effect of grounding the magneto 34 thereby preventing a sparkreaching the plug 42.

The drop in temperature of the evaporator 62 will lead the drop intemperature of the space to be refrigerated in the well-known manner.Moreover the size of the temperature differential between thefwalls ofthe evaporator 62 and the air in the space to be cooled will depend uponthe capacitative relationship of the cooling surface of the evaporatorto the space to be cooled. In order to prevent frequent cycling thedisabling switch 80 has its spring |50, schematically shown, so adjustedthat at a selected high .pressure in the conduit 66 and evaporator 62,the disabling switch will be in the position shown in the drawingvwhereas at a selected low pressure in the conduit 66 and evaporator 62,the bellows |54 will contract so that the arm |46 of the disablingswitch 80 moves into the dotted line position 204. Thus the bellows |54and spring |50 may be adjusted with respect to each other at ten poundsand twenty-seven pounds pressure. When the temperature in the evaporator62 and conduit 66 becomes sufiiciently high so that the pressure thereinis twenty-seven pounds', the spring |50 draws the arm |46 to the rightand closes the contacts |38 and |40. Conversely when the temperature inthe evaporator 62 and conduit 66 has dropped to a given point such thatthe pressure is, for example, ten pounds, the bellows |54 contracts,thereby opening the points |38 and |40 and closing the points |42 and|44.

When the engine 20 stops, the vacuum in the chamber |80 is slowlydissipated due to atmospheric pressure seeping past the disks and |93from the manifold side of the line |84. all located within the vacuumcontrol unit |84. The springs |88 and 20| controlling the movements ofthe -wafer valves |85 and |93 respectively. are of low tension and donot seat the valves sumciently firmly during idle periods to preventseepage of air from the manifold side of the line into the vacuumchamber |80. As the vacuum in the chamber |80 collapses, the choke 80moves into closed position and the bellows |26 expands and moves the armI I8 into the position shown. When this occurs, the refrigerant supplycircuit is thereby operated a-t contacts ||4||6 to allow closing of therefrigerant supply valve 54. The starter circuit contacts ||0| I2' ofswitch 18 are again closed but the starter 44 is not then energizedbecause the contacts |88 and |40 in the disabling switch 80 remain openso long as the sub-low pressure continues in the suction conduit 66. yItwill be appreciated that it is essential for the starter circuit to bebroken in the disabling switch 80 because during automatic operation themaster switch 'I6 remains closed and the starter circuit -must not beenergized until the spring |50 is able to overcome the collapsed bellows|54 due to a rise in temperature and consequently in pressure in theevaporator 62 and suction line 66.

It will be understood that applicants invention resides in thearrangement of circuits and the employment of a substantially constantvacuum chamber in connection with a four-cycle, single cylinder engine.The great advantage of applicants lsystem is that frequent cycling ofthe gasoline engine is avoided. It of course is recognized that frequentcycling in any refrigeration system is not very desirable although inthe case of systems powered with electric motors, the objection tofrequent cycling is not so great as in the case of a system powered byan internal combustion engine. It is desired not to use any more currentfrom the hot line 82 than is necessary for ordinarily this hot" line issupplied with current from a wet battery. Where applicants apparatus-ispositioned in a truck, the battery will ordinarily be charged by thetruck or tractor motor but it is desired to use just as little currentas possible.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent of the United States is:

1. A refrigerating apparatus including a fourcycle, single cylinderinternal combustion engine, an electric starter therefor, a compressordriven by said engine and positioned in a refrigerant Vcirculatingsystem, a starter circuit for conducting electric energy to the starter,means responsive to a reduced pressure in the engine manifold during theintake stroke therefor for breaking and holding open said startercircuit and means for preventing manifold pressures occurring during theother three strokes of the engine from affecting the starter circuit.

2. A refrigerating apparatus including a fourcycle, single cylinderinternal combustion engine, an electric starter therefor, a compressordriven by said engine and positioned in a refrigerant circulatingsystem, a starter circuit for conduct- 9 lng electric energy to thestarter. a switch normally closed in said circuit, means responsive to areduced manifold pressure duringV the intake stroke of said engine foropening said switch and means for preventing manifold pressuresoccurring during the other three strokes of the engine from closing saidswitch.

3. A refrigerating apparatus including a fourcycle, single cylinderinternal combustion engine, an electric starter therefona compressordriven by said engine and positioned in a refrigerant circulatingsystem, a starter circuit for conducting electric energy to the starter,a switch in' said starter circuit, a bellows connected to said switch'to open the same upon the reduction of presintake stroke only of saidengine during engine operation.

4. A refrigerating apparatus including a fourcycle, single cylinderinternal combustion engine, an electric starter therefor, a compressordriven by said engine and positioned in a refrigerant circulatingsystem, a starter circuit for conducting electric energy to the starter,a switch in said starter circuit, a bellows connected to said switch toopen the same upon the reduction of pressure in said bellows, a conduitconnecting said bellows to the inlet manifold of said engine, and meanspositioned in said conduit for' limiting the pres-v sure imposed therebyon the bellows to substantially the pressure obtaining during the intakestroke only of said engine during engine operation, said meanscomprising a valve adapted to open only when the pressure in the enginemanifold is less than the pressure in the bellows.

5. A refrigeratlng apparatus including a fourcycle, single cylinderinternal combustion engine, an electric starter therefor, a compressordriven by said engine and positioned in a refrigerant circulatingsystem, a starter circuit for conducting electric energy to the starter,e, switch in said starter circuit, a bellows connected to said switch toopen the same upon reduction of pressure in said bellows, a conduitconnecting said bellows to the intake manifold of said engine, and meanspositioned in said conduit for limiting the pressure imposed thereby onthe bellows to substantially the pressure obtaining during the intakestroke only of said engine during engine operation, said meanscomprising a chamber positioned in said conduit and a vacuum controlunit positioned between said chamber and the engine manifold, saidvacuum control unit having two wafer valves arranged in series thereinadapted to open only when the pressure in the chamber exceeds thepressure in the engine manifold.

6. A refrigerating apparatus including a fourcycle single cylinderinternal combustion engine, a compressor driven by said engine andpositioned in a refrigerant circulating system, an electric starter forsaid engine, an electric circuitl connected to a source of power forfunctioning said starter,` a solenoid controlled switch positioned insaid electric circuit, a starter circuit including the coil of saidsolenoid switch therein and normally connected to a source of power soas to hold said solenoid switch in closed position, means responsive tothe reduced -pressure of the intake stroke of said engine inthe'manifold for opening said starter circuit and thereby stopping thestarter, and means for preventing manifoldlpressures occurring duringthe other three strokes of the engine from affecting the startercircuit.

7. In a refrigerating apparatus of the linter-l mittent cycling typewherein a four-cycle single cylinder internal combustion carburetedengine driving a compressor positioned in a refrigerant -ginecarburetor, said choke being normally held in a closed position, andmeans responsive to the reduced pressure in said zone for moving saidchoke into an open position, whereby when the engine is at rest thestarter circuit and the carburetor will be in condition for quicklystarting the same and upon the enginegs starting. the

starter circuit will be disabled and the choke will cease to function..

8. In an automatic refrigerating the intermittent cycling type whereina, gas engine drives a compressor positioned in a refrigerantcirculating system and an electric starter is operably associated withthe gas engine; the combination of a starter circuit for supplyingelectric energy to the starter, switch means responsive to e, reducedpressure in the manifold of said engine for opening said startercircuit, and a second switch in said starter' circuit in series with thefirst switch and adapted to open said circuit in response to pressureconditions in the refrigerant circulating system.

9. In e, refrigerating apparatus of the intermittent cycling typewherein a four-cycle single cylinder gas engine drives a compressorpositioned in a refrigerant circulatory system including an evaporatorand wherein an electric starter is operably associated with said engine:the combination of a starter circuit forsupplying electric energy to thestarter, a starter break switch positoned in said starter circuit andmeans adapted to open said switch and hence said circuit in response toreduced pressure -in the en gine intake manifold during intake strokesof said engine, a, disabling switch mounted in said starter circuit inseries with said starter break switch and means for opening saiddisabling switch to open said starter circuit in accordance with aselected low temperature in the evaporator coils.

10. In a refrigerating apparatus of the intermittent operating typewherein a four-cycle, single cylinder gas engine drives a compressorpositioned in a refrigerant circulating system and an electric starteris operably connected to the gas engine: the combination of a starter.

circuit adapted to function the starter. circuit breaking meansresponsive solely to the reduced pressure of the intake stroke of saidengine for opening said starter circuit, switch means having one settingin which it is operable to open the starter circuit and concurrentlydisable the running of the engine and having another setting in which itcloses said starter circuit, and switch operating means responsive to areduced apparatus of pressure in the evaporator for incurring such opensetting of said switch means and responsive to a subsequent increase inthe evaporator pressure to incur such closed setting of said switchmeans, whereby when said switch operating means functions, the circuitbreaking means will cease to function because of the stopping of saidengine and the starter circuit is placed in readiness for functioningthe starter when the switch means resumes its closed setting.

11. In a refrigerating apparatus of the intermittent operating typeincluding ,a four-cycle. single cylinder gas engine driving a compressorin a refrigerant circulating system containing an evaporator and anelectric starter operably connected to the gas engine: the combinationoi' a starter circuit, a starter break switch responsive solely to thereduced pressure of the intake stroke of said engine for opening saidstarter circuit, a disabling circuit connected to the ignition circuitof the gas engine. disabling switch means having a component positionedin said starter circuit in series with said starter break switch to opensuch circuit, when such disabling switch means is operated to an opensetting and to close such circuit when such switch means is operated toa closed setting, said switch means also having a component in saiddisabling circuit for connecting the same to ground when the disablingswitch means is in theopen setting and to remove said ground connectionwhen the disabling switch means is in the closed setting and operatingmeans for said switch means to incur the open setting thereof inresponse to a decrease of pressure in the evaporator and to incur theclosed setting thereof in response to a subsequent increase of suchpressure.

12. In a refrigerating apparatus of the intermittent cycling typeincluding an ignition type gas engine driving a compressor in arefrigerant circulating system having an evaporator, a solenoidcontrolled valve 1n the line for supplying liquid refrigerant to saidevaporator and an electric starter operably connected to Lsaid gasengine: the combination of a starter circuit for energizing the starter,a disablingcircuit for grounding the engine ignition circuit to stopsaid engine. a refrigerant supply control circuit including the coil ofthe solenoid controlledvalve and adapted to open said valve whenenergized. and a multiple starter breakswitch positioned in the startercircuit and in the refrigerant supply control circuit, switch operatingmeans operable to open the starter circuit and close the refrigerantsupply control circuit in response to a reduced pressure derived solelyfrom the intake stroke of said engine when it is operating.. a disablingswitch posltioned'in the starter circuit in series with the starterbreak switch and also positioned in the engine disabling circuit, and asecond switch operating means operative upon said disabling switch toopen the starter circuit and close the disabling circuit concurrently inaccordance with a selected low temperature in the evaporator. v

13. The refrigerating apparatus described in claim 12 and an expansionvalve responsive to temperature conditions of the evaporator controllingthe supply of refrigerant to the evaporator.

14. In a refrigerating apparatus of the intermittent cycling typewherein a four-cycle, single cylinder gas engine drives a compressor ina refrigerant circulating system having an evaporator and wherein anelectric starter is operably g connected to the gas engine: thecombination of a starter circuit including switch means and adapted tofunction the starter until said switch means is opened, switch operatingmeans responsive solely to pressure variations of the intake stroke ofsaid engine to open said switch means, a disabling circuit connectiblewith ground for grounding the engine ignition circuit to stop saidengine, a disabling switch for connecting said disabling circuit withground, a, refrigerant supply controlling valve in the line forsupplying liquid refrigerant to the evaporator, a capillary control tubemounted on the evaporator and operably connected to said valve forshutting oiI the supply of the refrigerant to the evaporator when theevaporator has reached a selected low temperature, and means responsiveto the abnormally low pressure in the evaporator occurring after theshutting oil! of the refrigerant supply for operating said disablingswitch to ground said disabling circuit and thereby stop the gas engine.

THOMAS C. KIILORAN.

